Marcus Stroman, rhp, Blue Jays: When the Blue Jays drafted Stroman in the first round (22nd overall) last year out of Duke, the expectation was that he could move quickly to the big leagues. He reached Double-A New Hampshire as a reliever soon after signing, but a positive drug test for a stimulant led to a 50-game suspension that kept him off the field to begin 2013, a situation that was more of an inconvenience than a major red flag. He made his season debut yesterday for New Hampshire, throwing five shutout innings with six strikeouts and one walk. If the Blue Jays are still in the cellar of the American League East at midseason, there might not be an incentive to call up Stroman, but it shouldn't take him long before he's big league ready.
Kyle Gibson, rhp, Twins: We don't see many nine-inning shutouts in the minor leagues, but that's exactly what Gibson did for the second time in his last three starts for Rochester. Yesterday Gibson threw nine scoreless innings against Triple-A Lehigh Valley, allowing three hits, two walks while striking out eight. As he recovered from Tommy John surgery last year he never pitched beyond the fifth inning (including a stint in the Arizona Fall League), but he needed just 93 pitches yesterday to finish the job. Gibson, 25, is showing the stuff of a potential No. 3 starter, and he's not far from from being ready to contribute in Minnesota.
Chris Colabello, 1b, Twins: You can talk about how Colabello is a 29-year-old in Triple-A, and sure, that does matter, because we're not going to project someone who's 29 the same way we would a 23-year-old. But Colabello's isn't your typical 4-A, journeyman minor leaguer. He spent eight years playing independent ball, mashed in Double-A last year when he finally got his chance in affiliated baseball and now is second in the Triple-A International League in OPS after collecting four more hits yesterday for Rochester while playing right field for the second time this year, raising his slash line to .348/.405/.640 in 43 games. At some point, whether it's in a Twins uniform or not, Colabello's bat is going to force his way into the big leagues.
Cesar Puello, rf, Mets: Puello has been a frustrating prospect. He'll show flashes of brilliance, plus raw power, an above-average arm and the speed that helped him steal 45 bases in 109 games there years ago. Yet he's never been able to have that breakthrough that some scouts had expected from him. Until, perhaps, this year. Early in his career, Puello struggled with his hitting approach and to generate loft in his swing to be able to tap into his raw power. This year he's shown a more selective hitting approach and his swing plane has continued to evolve to help him drive the ball out of the park, which is why he's hitting .305/.369/.508 with five home runs in 33 games at Double-A Binghamton. This might just be the breakout the Mets have been waiting for.
Dilson Herrera, 2b, Pirates: Last year the Pirates had Gregory Polanco and Alen Hanson enjoying breakout years in low Class A West Virginia. While Hanson has struggled early in 2013 and Polanco has elevated his status into one of the game's true premium prospects, the Pirates have another hitter from their Latin American program making noise in West Virginia. Herrera went 4-for-4 with a double and a home run on Friday, and while he went hitless the last two days he's still hitting .296/.358/.458 in 36 games. Herrera doesn't have the speed or athleticism than Polanco and Hanson have, but he has a natural feel for hitting and a skill set that projects as an offensive-oriented second baseman.
Matt Barnes, rhp, Red Sox: The first four starts of the year were a disaster for Barnes, who ended April having allowed 14 runs in as many innings in Double-A Portland. Since the calendar flipped to May, Barnes has been one of the best pitchers in the minors, with a 1.96 ERA and a 28-7 K-BB mark in 23 innings over four starts. Barnes' fastball has as much zip as ever, sitting at 92-95 mph and touching 97, so one of the keys for him will be the refinement of his secondary pitches, particularly a changeup that has been his No. 3 pitch since he signed.
Mike Foltynewicz, rhp, Astros: After topping out in the mid-90s his first year in the organization, Foltynewicz repeated the low Class A South Atlantic League in 2012, saw improved results and added a few ticks to his fastball. Now Foltynewicz sits in the mid-90s, touches 100 mph and is missing more bats than ever pitching in short stints. Promoted to Double-A Corpus Christi at the start of the month, the 21-year-old has a 1.13 ERA in 16 innings with 17 strikeouts and six walks.